한국 여성에서 자궁내막증과 GSTM1, GSTT1 유전자 결손 다형성의 연관성

김태준 ( Kim Tae Jun ),김석현 ( Kim Seog Hyeon ),최영민 ( Choi Young MIn ),전종관 ( Jun Jong Kwan ),박성효 ( Park Seong Hyo ),박인애 ( Park In Ae ),구승엽 ( Ku Seung Yup ),서창석 ( Suh Chang Suk ),김정구 ( Kim Jeong Gu ),문신용 ( 대한산부인과학회 2003 Obstetrics & Gynecology Science Vol.46 No.7

목적 : Phase Ⅱ glutathione S-transferase mu, theta 효소 유전자 (GSTM1, GSTT1) 결손 다형성과 자궁내막증의 연관성을 알아보고자 하였다. 연구 방법 : 복강경술 또는 개복술로 자궁내막증으로 진단된 환자 148명과 복강경술 또는 개복술에서 자궁내막증이 없는 것으로 확인된 대조군 130명을 대상으로 하여, GSTM1 및 GSTT1 유전자의 결손 다형성 여부를 조사하였다. 결과 : 자궁내막증 환자와 대조군 사이에 GSTM1 유전자 결손 다형성 (GSTM1 0/0)의 빈도는 유의한 차이를 보였으나 (61.5% vs 49.2%, p=0.040), GSTT1 유전자 결손 다형성 (GSTT1 0/0)의 빈도는 차이가 없었다 (51.4% vs 54.6%, p>0.1). GSTM1 유전자의 경우 stage Ⅲ-Ⅳ인 중증 자궁내막증과 유의한 상관 관계를 보였으나 stage Ⅰ-Ⅱ인 경한 자궁내막증과는 유의한 차이를 보이지 않았다. 결론 : GSTM1 유전자 결손 다형성과 한국 여성에서 자궁내막증 발생과 연관이 있었으며, GSTT1 유전자 결손 다형성과는 관련이 없었다. Objective : To explore the association of the phase Ⅱ glutathione S-transferase mu (GSTM1), theta (GSTT1) gene null polymorphisms with endometriosis in a Korean population. Methods : One hundred forty eight women with surgically diagnosed endometriosis of stage Ⅰ-Ⅳ were recruited. And 130 patients with no evidence of endometriosis by laparoscopy or laparotomy served as controls. Genomic DNA was extracted from peripheral blood and analyzed for GSTM1, GSTT1 null polymorphisms. Results : GSTM1 null genotype (GSTM1 0/0) was found more frequently in patients with endometriosis than in controls (61.5% in endometriosis vs. 49.2% in control, p=0.040). And the association was found only in moderate to severe endometriosis (stage Ⅲ Ⅳ) (63.7% vs. 49.2%, p=0.027: odds ratio: 1.812), not in minimal or mild endometriosis (p=0.395). There was no significant difference between endometriosis patients and controls in the frequency of the GSTT1 null genotype (51.4% vs. 54.6%, p>0.1). Conclusion : These results suggest that GSTM1 null genotype is associated with the risk of endometriosis but GSTT1 null genotype is not in the Korean population.

Meta-analysis of the Association Between GSTM1 and GSTT1 Gene Polymorphisms and Cervical Cancer

Zhang, Zhen-Yong,Jin, Xue-Ying,Wu, Rong,Wu, Li-Na,Xing, Rui,Yang, Shu-Juan,Xie, Yao Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.3

Aim: We conducted a meta-analysis to analyze the influence of GSTM1 and GSTT1 gene polymorphisms on cervical cancer risk, and explore gene-environment interactions. Methods: Identification of relevant studies was carried out through a search of Medline and the EMbase up to Oct. 2011. All case-control studies that investigated the association between GSTM1 and GSTT1 gene polymorphisms and risk of cervical cancer were included. The pooled odds ratio (OR) was used for analyses of results and the corresponding 95% confidence intervals (CI) were estimated. Results: A total of 21 case-control studies were included in the meta-analysis of GSTM1 (2,378 cases and 2,639 controls) and GSTT1 (1,229 cases and 1,223 controls) genotypes. The overall results showed that the GSTM1 null was related to an increased risk of cervical cancer (OR=1.50, 95% CI=1.21-1.85). Subgroup analysis were performed based on smoking and ethnicity. Our results showed that smokers with null GSTM1 genotype had a moderate increased risk of cervical cancer (OR=1.85, 95% CI=1.07-3.20). For the ethnicity stratification, moderate significantly increased risk of null GSTM1 genotype was found in Chinese (OR=2.12, 95% CI=1.43-3.15) and Indian populations (OR=2.07, 95% CI=1.49-2.88), but no increased risk was noted in others. Conclusion: This meta-analysis provided strong evidence that the GSTM1 genotype is associated with the development of cervical cancer, especially in smokers, and Chinese and Indian populations. However, no association was found for GSTT1 null genotype carriers.

Distributions of the GSTM1 and GSTT1 Null Genotypes Worldwide are Characterized by Latitudinal Clines

Saitou, Marie,Ishida, Takafumi Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.1

Background: Deletion types of genetic variants of glutathione S-transferase (GST) M1 and T1, the GSTM1 null and GSTT1 null which are risk factors for certain cancers, have been ubiquitously found in human populations but their worldwide distribution pattern is unclear. Materials and Methods: To perform a meta-analysis, a systematic search for the literature on GSTM1 and GSTT1 null genotypes was done to identify 63 reports for 81 human populations. Relationships between the GSTM1 and GSTT1 null genotype frequencies and the absolute latitude of 81 populations were tested by Spearman's rank correlation coefficient. Results: A significant positive correlation was detected between the GSTM1 null genotype frequency and the absolute latitude (r=0.28, p-value <0.05), whereas the GSTT1 null genotype frequency and absolute latitude showed a significant negative correlation (r= -0.41 p-value <0.01). There was no correlation between the frequencies of GSTM1 and GSTT1 null genotype in each population (r= -0.029, p-value=0.80). Conclusions: Latitudinal clines of the distribution of the GSTM1 and GSTT1 null genotypes may be attributed to the result of gene-environmental adaptation. No functional compensation between GSTM1 and GSTT1 was suggested by the lack of correlation between the null frequencies for GSTM1 and GSTT1.

Genetic Susceptibility to Oral Cancer due to Combined Effects of GSTT1, GSTM1 and CYP1A1 Gene Variants in Tobacco Addicted Patients of Pashtun Ethnicity of Khyber Pakhtunkhwa Province of Pakistan

Zakiullah, Zakiullah,Ahmadullah, Ahmadullah,Khisroon, Muhammad,Saeed, Muhammad,Khan, Ajmal,Khuda, Fazli,Ali, Sajid,Javed, Nabila,Ovais, Muhammad,Masood, Nosheen,Khalil, Nasir Khan,Ismail, Mohammad Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.3

Associations of GSTT1, GSTM1 and CYP1A1 gene variants with risk of developing oral cancer were evaluated in this study. A case-control study was conducted in Pashtun population of Khyber Pakhtunkhwa province of Pakistan in which 200 hospital based oral cancer cases and 151 population based healthy controls exposed to similar environmental conditions were included. Sociodemographic data were obtained and blood samples were collected with informed consent for analysis. GSTM1 and GSTT1 were analysed through conventional PCR method while specific RT-PCR method was used to detect CYP1A1 polymorphisms. Results were analyzed for conditional logistic regression model by SPSS version 20. The study shows that patients with either GSTM1 or GSTT1 null genotypes have significantly higher risk of oral cancer (adjusted odds (OR): (3.019 (1.861-4.898) and 3.011(1.865-4.862), respectively), which further increased when either one or both null genes were present in combination (adjusted odds (OR): (3.627 (1.981-6.642 and 9.261 (4.495-19.079), respectively). CYP1A1 rs4646903 gene variants individually showed weak association OR: 1.121 (0.717-1.752); however, in the presence of GSTM1 and/or GSTT1 null genotypes further increasing the association (adjusted odds (ORs): 4.576 (2.038-10.273), 5.593 (2.530-12.362) and 16.10 (3.854-67.260 for GSTM/GSTT null and CYP1A1 wild type, GSTM/GSTT either null and CYP1A1 variant alleles, and all 3 gene polymorphisms combinations, respectively). Our findings suggest that presence of GSTM1 and/or GSTT1 null genotypes along with variant alleles of CYP1A1 may be the risk alleles for oral cancer susceptibility in Pashtun population.

GSTM1과 GSTT1, 그리고 CYP1A1, CYP2E1 다형성이 폐암발생에 미치는 영향에 대한 환자-대조군연구

남홍매,강종원,배장환,최강현,이기형,김승택,원중희,김용민,김헌,Nan, Hong-Mei,Kang, Jong-Won,Bae, Jang-Whan,Choe, Kang-Hyeon,Lee, Ki-Hyeong,Kim, Seung-Taik,Won, Choong-Hee,Kim, Yong-Min,Kim, Heon 대한예방의학회 1999 예방의학회지 Vol.32 No.2

1997년 3월부터 1998년 6월까지 충북대학교병원 내과에 입원하여 치료를 받은 폐암환자 98명과 암 아닌 다른 질환을 가진 대조군 98명을 대상으로 흡연, 음주, 여러 가지 질병과거력 등을 포함한 생활습관과, GSTM1과 GSTT1, 그리고 CYP1A1, CYP1E1 유전자 다형성 양상을 조사하여 다음과 같은 결론을 얻었다. 1. GSTM1의 결손은 환자군이 67.01%, 대조군이 58.16%로 확인되었으며, OR(95% CI)이 1.46(0.82-2.62)으로 폐암 발생에 대해 유의한 영향을 미치지 않는 것으로 나타났다. 2. GSTT1의 결손은 환자군이 58.76%, 대조군이 50.00%로 확인되었으며, OR (95% CD가 1.43(0.81-2.51)으로 폐암 발생과 관련이 없는 것으로 나타났다. 3. CYP1A1 유전자 다형성은 Ile/Ile, Ile/Val, Val/Val 환자군이 각각 59.18%, 35.71%, 5.10%, 대조군이 각각 52.04%, 45.92%, 2.04%로 CYP1A1 유전자 다형성과 폐암 위험도 사이의 관련성은 유의하지 않은 것으로 나타났다$(x^2trend=0.253,\;p-value>0.05)$. 4. CYP1E1 유전자 다형성은 c1/c1, c1/c2, c2/c2 형 이 환자군에서 각각 50.00%, 42.86%, 7.14%, 대조군에서 각각 66.33%, 30.61%, 3.06%로 CYP1E1 활성이 폐암 발생에 유의한 영향을 미치는 것으로 나타났다$(x^2trend=5.783,\;p-value<0.05)$. 특히 환자군이 대조군에 비하여 아주 드문 대립유전자인 c2형이 더 많은 것으로 나타났다. 5. 폐암과 밀접한 연관이 있는 흡연습관의 OR(95% CI)이 3.03(1.58-5.81)으로 확인되어, 폐암의 위험인자로 재확인 되었다. 6. GSTM1, GSTT1, CYP1A1, CYP2-E1과 흡연습관을 포함한 다변량 분석에서 흡연습관만이 유의한 폐암의 위험인자로 나타났다. 이 결과로부터 위의 4가지 유전자의 다형성이 폐암발생에 미치는 영향은, 흡연을 포함한 환경적 요인에 비하여 크지 않을 것으로 판단된다. Objectives: This study was performed to investigate sweets of genetic polymorphisms of glutathione S-transferase M1 (GSTM1), glutathione S-transferase M1 (GSTT1), cytochrome P450 1A1 (CYP1A1) and cytoehrome P450 2E1 (CYP2E1) on lung cancer development. Methods: Ninety-eight lung cancer patients and 98 age-sex matched non-cancer patients hospitalized in Chungbuk National University Hospital form March 1997 to August 1998, were the subjects of this case-control study. Direct interview was done and genotypes of GSTM1, GSTT1, CYP1A1 and CYP2E1 were investigated using multiplex PCR or PCR-RFLP methods with DNA extracted from venous blood. Effects of the polymorphisms of GSTM1, GSTT1, CYP1A1 and CYP2E1, lifestyle factors including smoking, and their interactions on lung rancor were statistically analyzed. Results: GSTM1 was deleted in 67.01% of the cases and 58.16% of the controls, and the odds ratio(95% CI) was 1.46(0.82-2.62). GSTT1 deletion was 58.76% for the lung cancer patients and 50.00% for the controls[OR:1.43(0.81-2.51)]. The frequencies of lle/lle, lle/Val and Val/Val of the CYP1A1 polymorphisms were 59.18-18%, 35.71%, and 5.10% for the cases, and 52.04%, 45.92%, 2.04% for the controls, respectively. Risk of lung cancer was not associated with polymorphism of CYP1A1 ($x^2trend=0.253$, p-value>0.05). The respective frequency of c1/c1 c1/c2, c2/c2 genotypes for CYP2E1 were 50.00%, 42.86%, 7.14% for the lung cancer patients, and 66.33%, 30.61%, 3.06% for the controls $(x^2trend=5.783,\;p<0.05)$. c2 allele was a significant risk factor for lung cancer. We also observed a significant association of cigarette smoking history with lung cancer risk. The odds ratio(95% Cl) of cigarette smoking was 3.03(1.58-5.81). In multiple logistic analysis including genotypes of GSTM1, GSTT1, CYP1A1 and CYP2E1, and smoking habit, only snaking habit came out to be a significant risk factor for lung cancer. Conclusion: Genetic polymorphisms of GSTM1, GSTT1, CYP1A1 and CYP2E1 are not so strongly associated with lung cancer as lifestyle factors including cigarette smoking.

Dimethylformamide 취급 근로자에서의 CYP2E1, GSTM1, GSTT1 유전자 다형성과 N-methylformamide 배설량간의 관련성

김재일,이충한,이용환 KOSIN UNIVERSITY COLLEGE OF MEDICINE 2006 高神大學校 醫學部 論文集 Vol.21 No.1

Background: N,N-dimethylformamide (DMF) has excellent solvent properties and is used intensively in the production of synthetic leather and resins. It has known to induce hepatotoxicity in human and animal by absorbing it through the lungs and skin. The metabolic transformation of DMF takes place mainly in the liver, with the aid of microsomal enzyme systems including cytochrome P450 (CYP), and glutathione S-transferase (GST). In metabolic studies and biological monitoring, urinary concentrations of metabolites are measured and expressed as N-methylformamide (NMF). This study examined the associations of the genetic polmorphism of CYP2E1. GSTM1 and GSTT1 with DMF metabolism. Methods: The subjects were 30 workers who exposed to DMF in a synthetic leather factory. Their urinary samples were collected and NMF concentrations were measured. Also, DMF concentrations in air were measured by personal air sampler during thier work. Genotypes of CYP2E1, GSTM1 and GSTT1 were investigated using PCR-RFLP or multiolex PCR methods with DNA extracted from venous blood. Effects of the polymorphisms of CYP2E1, GSTM1 and GSTT1 on DMF metabolism were analyzed. Results: The frequency of c1/c1 and c1/c2 genotypes for CYP2E1 were 76.6% and 23.3%, respectively. GSTM1 was deleted in 53.3% and GSTT1 deletion rate was 40.0%. In the group of GSTM1 deletion, mean urinary NMF concentrations (95.2 mg/g creatinine) were significantly higher than the undeleted group (45.3 mg/g creatinine, p=0.042). There were no significant differences of mean urinary NMF concentrations in the groups with the defferent genotypes of CYP2E1 and GSTT1. The distribution of CYP2E1, GSTM1 and GSTT1 genotypes by urinary NMF concentrations had not statistical significance. Conclusions: In GSTM1 deleted workers who exposed to DMF, mean urinary NMF concentration was higher than undeleted cases. GSTM1 deleted workers are seemed to be more susceptible to DMF toxicity. It is necessary to screen whether the workers have GSTM1 deleted genotype or not when they are arranged to their work place.

Glutathione-S-transferase (GSTM1, GSTT1) Null Phenotypes and Risk of Lung Cancer in a Korean Population

Piao, Jin-Mei,Shin, Min-Ho,Kim, Hee Nam,Cui, Lian-Hua,Song, Hye-Rim,Kweon, Sun-Seog,Choi, Jin-Su,Kim, Young-Chul,Oh, In-Jae,Kim, Kyu-Sik Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.12

Purpose: The aim of this study was to evaluate any association of GSTM1 and GSTT1 null genotypes with the risk of lung cancer in a South Korean population. Methods: We conducted a large-scale, population-based case-control study including 3,933 lung cancer cases and 1,699 controls. Genotypes of GSTM1 and GSTT1 were determined using real-time polymerase chain reaction. Results: In logistic regression analysis adjusted for age and smoking, we did not find any association between GSTM1 or GSTT1 and LC risk in women. However, in men, the GSTM1 and GSTTI null genotypes were borderline associated with risk (OR=1.18, 95% CI=0.99-1.41 for GSTM1, OR=1.18, 95% CI=0.99-1.41 for GSTT1), and combined GSTM1 and GSTT1 null genotypes conferred an increased risk for LC in men (OR=1.39, 95% CI=1.08-1.78). The OR for the GSTT1 null genotype was greater in subjects aged 55 years old or younger (OR=1.45, 95% CI=1.09-1.92 for men; OR=1.36, 95% CI=0.97-1.90 for women), than in those over age 55 (OR=1.03, 95% CI=0.83-1.27 for men; OR=0.86, 95% CI=0.66-1.12 for women) in both genders (p for interaction <0.05). Conclusions: In the Korean population, the GSTM1 and GSTT1 null genotypes are risk factors for LC in men; the GSTT1 null genotype has a more prominent effect on LC risk in younger people (age 55 years and under) than in older individuals.

Lack of Associations between Genetic Polymorphisms in GSTM1, GSTT1 and GSTP1 and Pancreatic Cancer Risk: A Multi-Institutional Case-Control Study in Japan

Yamada, Ikuhiro,Matsuyama, Masato,Ozaka, Masato,Inoue, Dai,Muramatsu, Yusuke,Ishii, Hiroshi,Junko, Ueda,Ueno, Makoto,Egawa, Naoto,Nakao, Haruhisa,Mori, Mitsuru,Matsuo, Keitaro,Nishiyama, Takeshi,Ohkaw Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.1

Background: We aimed to evaluate the role of genetic polymorphisms in tobacco carcinogen-metabolizing genes and their interactions with smoking in a hospital-based case-control study of Japanese subjects. Materials and Methods: We examine the associations of pancreatic cancer risk with genetic polymorphisms in GSTM1, GSTT1 and GSTP1, phase II enzymes that catalyze the conjugation of toxic and carcinogenic electrophilic molecules. The study population consisted of 360 patients and 400 control subjects, who were recruited from several medical facilities in Japan. Unconditional logistic regression methods were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the associations between genotypes and pancreatic cancer risk. Results: Among the control subjects, the prevalence of the GSTM1-null genotype and the GSTT1-null genotype was approximately 56% and 48%, respectively. Cases and controls were comparable in terms of GSTM1 and GSTT1 genotype distributions. Neither of the deleted polymorphisms in GSTM1 and GSTT1 was associated with the risk of pancreatic cancer, with an age- and sex-adjusted OR of 0.99 (95%CI: 0.74-1.32) for the GSTM1-null genotype, and 0.98 (95%CI: 0.73-1.31) for the GSTT1-null genotype. The OR was 0.97 (95%CI: 0.64-1.47) for individuals with the GSTM1 and GSTT1-null genotypes compared with those with the GSTM1 and GSTT1- present genotypes. No synergistic effects of smoking or GST genotypes were observed. Conclusions: Our results indicate no overall association between the GSTM1 and GSTT1 deletion polymorphisms and pancreatic cancer risk in the Japanese subjects in our study.

Dimethylfonriamide 취급 근로자에서의 CYP2E1, GSTM1, GSTT1 유전자 다형성과 N-iwthylformainide 배설량간의 관련성

김재일,이충한,이용환 고신대학교(의대) 고신대학교 의과대학 학술지 2006 고신대학교 의과대학 학술지 Vol.21 No.1

Background: N^N-Dimethylformamide (DMF) has excellent solvent properties and is used intensively in the production of synthetic leather and resins. It has known to induce hepatotoxicity in human and animal by absorbing it through the lungs and skin. The metabolic transformation of DMF takes place mainly in the liver, with the aid of microsomal enzyme systems including cytochrome P450 (CYP)S and glutathione S-transferase (GST). In metabolic studies and biological monitoring, urinary concentrations of metabolites are measured and expressed as N-methylformamide (NMF). This study examined the associations of the genetic polymorphism of CYP2E1, GSTM1 and GSTTl with DMF metabolism. Methods: The subjects were 30 workers who exposed to DMF in a synthetic leather factory. Their urinary samples were collected and NMF concentrations were measured. Also,DMF concentrations in air were measured by personal air sampler during their work. Genotypes of CYP2E1, GSTM1 and GSTTl were investigated using PCR-RFLP or multiolex PCR methods with DNA extracted from venous blood. Effects of the polymorphisms of CYP2E1,GSTM1 and GSTTl on DMF metabolism were analyzed. Results: The frequency of cl/cl and cl/c2 genotypes for CYP2E1 were 76,6% and 23.3%,respectively. GSTM1 was deleted in 533% and GSTTl deletion rate was 40.0%. In the group of GSTM1 deletion, mean urinary NMF concentrations (95,2 mg/g creatinine) were significantly higher than the undeleted group (45.3 mg/g creatinine, p=0,042乂 There were no significant differences of mean urinary NMF concentrations in the groups with the different genotypes of CYP2E1 and GSTTl. The distribution of CYP2E1, GSTM1 and GSTTl genotypes by urinary NMF concentrations had not statistical significance. Conclusions: In GSTM1 deleted workers who exposed to DMF, mean urinary NMF concentration was higher than undeleted cases. GSTM1 deleted workers are seemed to be more susceptible to DMF toxicity, It is necessary to screen whether the workers have GSTM1 deleted genotype or not when they are arranged to their work place,

Genetic Polymorphism of GSTM1 and GSTT1 and Risk of Prostatic Carcinoma - a Meta-analysis of 7,281 Prostate Cancer Cases and 9,082 Healthy Controls

Malik, Saima Shakil,Kazmi, Zehra,Fatima, Iffat,Shabbir, Riffat,Perveen, Shagufta,Masood, Nosheen Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.5

Genetic polymorphisms constitute one of the reasons behind the racial variation in prostate cancer occurrence. Published studies regarding genetic associations of glutathione S-transferase mu 1 (GSTM1) and glutathione S-transferase theta 1 (GSTT1) null deletion polymorphisms with prostatic carcinoma have generated inconsistent results among different populations. To date, even a single meta-analysis is not available representing the association of these genes with prostate cancer in different ethnic groups. Therefore, the aim of the current study was to provide a clear picture of GSTM1 and GSTT1 null deletion and risk of prostate cancer among different ethnic groups (i.e. Asians, Europeans, Americans, Africans and Eurasians). A systematic search was performed with the help of various search engines to find out the all the recent studies (2004 to 2015) evaluating the role of GSTM1 and GSTT1 deletion in prostate cancer development. Odds ratios (ORs) with 95% confidence interval (CI) of a total of 34 studies with 7,281 cases and 9,082 controls was analyzed using STATA and MedCalc software. Overall, GSTM1 deletion (OR 3.67; CI 1.39-9.85; P= 0.001) was strongly associated with prostatic cancer. In the sub group analysis GSTM1 null deletion was also significantly associated with prostate cancer among Asians (OR 4.84; CI 1.08-21.5; P= 0.03), Eurasians (OR 17.69; CI 9.87-31.70; P< 0.001) and Americans (OR 0.11; CI 0.01-1.06; P= 0.05). No association was observed among Europeans (P=0.42) and Africans (P= 0.40). As a whole GSTT1 null deletion (OR 0.85; CI 0.28-2.58; P= 0.77) did not show anyt significant association with prostate cancer risk among different populations. When the data were stratified into different groups, however, Africans demonstrated a significant association of GSTT1 null deletion (OR 1.95; CI 1.57-2.39; P<0.001) with prostate cancer, whereas no association was found among Asians (P= 0.90), Americans (P= 0.50), Europeans (P= 0.89) and Eurasians (P= 1.0). In conclusion, both GSTM1 and GSTT1 may contribute to prostate cancer development but GSTM1 may prove to be a stronger candidate risk factor.